GROUND COVER NO-TILL
20
NUTRIENT MANAGEMENT
WA: wet or dry, no-till beats tradition
THE CHANGE TO CONSERVATION FARMING NEEDED HARD WORK AND
PERSEVERANCE FOR A TAMMIN COUPLE. NOW THAT THE EFFECT ON
THEIR BOTTOM LINE IS CLEAR, THERE IS NO GOING BACK
A visiting US agricultural researcher has urged
Australian R&D corporations to invest in
researching ground cover crops after seeing the
quick dividends they paid in Australian soils.
Professor Perry Miller, a keynote speaker at
a number of no-till farming conferences across
Australia in 2004, said he was surprised at
the rapid payback in productivity from brown
manure or 'ground cover' crops in Western
Australia.
"We typically must wait five or six years
to see a shift in soil quality associated with
ground cover crops," he said. "Rotational
benefits from pulse crops are primarily
associated with soil nitrogen dynamics, rather
than soil water."
He said it appeared that the function of soil
organic matter was even more critical in some
Australian soils, particularly in the southern
and western wheatbelt than in the northern
Great Plains of North America.
"If I held the purse strings to your research
budget, I'd invest aggressively in understanding
the role of ground cover crops, as it seems to
offer a much quicker payback here."
Professor Miller's US work looked at
rotational benefits and the long-term effects of
diverse rotations on things such as soil nutrient
dynamics and soil carbon sequestration.
He found greater crop diversity paid off by
delivering real dividends. "All cropping systems
must increase rotational diversity if they are
to overcome sustainability issues," he said.
"Concerns with rising groundwater, soil salinity,
soil organic matter and soil health can all
be addressed through prudent use of plant
species."
Soil water balance can be affected by
the rooting depth of crops and may impact
on the yield of subsequent crops, according
to Professor Miller: "This is important in the
northern Great Plains, but will have to be
studied in context. Australia's old soils are very
different from our young soils."
He proposed that Australian growers
particularly look beyond their traditional grain
crops of wheat, barley and canola.
"Diversified cropping systems have
increased rapidly in Canada and have the
potential to do the same in other semi-arid
regions. Therefore, it is important to understand
how flexibility in cropping systems is increased
by including broadleaf crops. Importantly,
a grain-yield advantage for no-tillage over
conventional grain production systems
occurs in diversified crop rotations containing
broadleaf crops."
THE ABILITY TO establish healthy crops despite
the poor start to the season has convinced Western
Australian No-Tillage Farmers Association
(WANTFA) members Colin and Libby Hutchinson of
Tammin that their no-till farming system will make a
significant impact on their bottom line this year.
Just 26 millimetres of rainfall during April and May
did not deter the Hutchinsons from sowing their entire
4000-hectare program at the usual time, and in the
middle of July they had some of the most advanced
crops in the central wheatbelt.
“In a good year it doesn’t really matter what you
do,” Mr Hutchinson says. “But in the very dry or very
wet years, the no-till system has proven to outweigh
INVEST IN GROUND COVER CROPS: US RESEARCHER
Perry Miller on America's northern Great
Plains: "Australia's old soils are very
different from our young soils."